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| author | Anton Vorontsov <anton.vorontsov@linaro.org> | 2012-07-09 17:10:42 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-07-17 10:07:00 -0700 |
| commit | 21f679404a0c28bd5b1b3aff2a7218bbff4cb43d (patch) | |
| tree | 9a5f1d0be079dfe225e2993331f9ddfac36cb7fc /kernel/trace | |
| parent | 060287b8c467bf49a594d8d669e1986c6d8d76b0 (diff) | |
| download | blackbird-op-linux-21f679404a0c28bd5b1b3aff2a7218bbff4cb43d.tar.gz blackbird-op-linux-21f679404a0c28bd5b1b3aff2a7218bbff4cb43d.zip | |
tracing/function: Introduce persistent trace option
This patch introduces 'func_ptrace' option, now available in
/sys/kernel/debug/tracing/options when function tracer
is selected.
The patch also adds some tiny code that calls back to pstore
to record the trace. The callback is no-op when PSTORE=n.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/trace_functions.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index c7b0c6a7db09..13770abd7a12 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -13,6 +13,7 @@ #include <linux/debugfs.h> #include <linux/uaccess.h> #include <linux/ftrace.h> +#include <linux/pstore.h> #include <linux/fs.h> #include "trace.h" @@ -74,6 +75,14 @@ function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip) preempt_enable_notrace(); } +/* Our two options */ +enum { + TRACE_FUNC_OPT_STACK = 0x1, + TRACE_FUNC_OPT_PSTORE = 0x2, +}; + +static struct tracer_flags func_flags; + static void function_trace_call(unsigned long ip, unsigned long parent_ip) { @@ -97,6 +106,12 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) { + /* + * So far tracing doesn't support multiple buffers, so + * we make an explicit call for now. + */ + if (unlikely(func_flags.val & TRACE_FUNC_OPT_PSTORE)) + pstore_ftrace_call(ip, parent_ip); pc = preempt_count(); trace_function(tr, ip, parent_ip, flags, pc); } @@ -158,15 +173,13 @@ static struct ftrace_ops trace_stack_ops __read_mostly = .flags = FTRACE_OPS_FL_GLOBAL, }; -/* Our two options */ -enum { - TRACE_FUNC_OPT_STACK = 0x1, -}; - static struct tracer_opt func_opts[] = { #ifdef CONFIG_STACKTRACE { TRACER_OPT(func_stack_trace, TRACE_FUNC_OPT_STACK) }, #endif +#ifdef CONFIG_PSTORE_FTRACE + { TRACER_OPT(func_pstore, TRACE_FUNC_OPT_PSTORE) }, +#endif { } /* Always set a last empty entry */ }; @@ -218,6 +231,8 @@ static int func_set_flag(u32 old_flags, u32 bit, int set) } return 0; + } else if (bit == TRACE_FUNC_OPT_PSTORE) { + return 0; } return -EINVAL; |
